Section 8: Sleep 8% Flashcards

1
Q

Outline the most important brain structures that play a role in circadian rhythm

A

Internal clock. Coordinated by the Supra Chiasmatic Nucleus (SCN) deep in hypothalamus.
SCN coordinates all other clocks in major body organs (peripheral clocks)
Roughly a 24hr period associated with daylight and darkness
Activity and eating are additional stimuli which influence the clock
Body clock influences digestion, hormone secretion, eating and sleeping
peripheral oscilators present in every major organ in body (kidneys, liver, heart, adrenal glands, pancreas)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the external and environmental factors that can ENTRAIN circadian rhythm? (5)

A
INPUTS: (external and environmental factors that can entrain circ rhythm) 
Light intensity
Light wavelegth
Food carbohydrates
Fluids (osmolality)
Ambient temperature
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the modifiers of sleep and what do they do?

A

MODIFIERS: Change the amount of input that gets to the body’s operators

  1. Pupilary reflex -limits the amount of light that gets into retina gangl. cells
  2. Sunglasses/ backlight on electronic devices (change the intensity of light reaching retinal ganglion cells)
  3. PER & CRY SNPs (Single Nucleotide Polymorhisms- genet variation in the DNA; PER and CRY proteins integral to circ rhythm)
  4. Cutaneous fat stores- affects core and extremity temp by acceleratin (little fat) or dampening (lot of fat) the thermoreg. response
  5. Vascular tone (NO, E2, Na)- affects fl vol in bl ves which modifies core and periph temp : NO and E2 vasodilation, Na => vasoconstriction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

waht are the operators of sleep? (4)

A

= body’s reaction or response to modified inputs:

  1. core body temp
  2. melatonin (produced in pineal gland)
  3. cortisol
  4. cutaneous blood flow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the “outputs” of sleep?

A

behavioural and physiological consequences of the operators: 1. sleep

  1. functional performance, including: alertness, kinetic activity, motor skills, incl. orecision,, strength and stamina
  2. food seeking behaviour, incl QUANTITY AND QUALITY
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What proportion of workers are estimated to be on night shifts in the US?

A

20%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what proportion of US adults sleeps < 6hrs/ night?

A

20%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the average duration of sleep for US adults?

A

6hrs 57 min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what proportion of young aults sleep less then 7 hours a night?

A

37% (this doubled since 1960’s)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how many of US adults are estimated to have difficulties sleeping?

A

60mil (only 10% seek medical attn)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what proportion of life is estimated to be spent sleeping?

A

1/3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the agreed number for general requirements for sleep?

A

7-9, considerable range of subjective need

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what physiological process occur during sleep?

A
  • cell cycle, apoptosis and DNA remodelling and repair
  • Drug metabolism and detoxification
  • angiogenesis
  • LEPTIN secretion (controls appetite)
  • gradual increase in cortisol
  • fatty acid metabolism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

briefly outline melatonin physiology and its role in circadian rhythm

A
  1. produced in pineal gland in response to melanopsin (pigment formed in RGC - retinal ganglion cells) - maximally sensitive to blue light 480nm (shortest wave legth)
  2. inputs and modifiers affect how much melatonin is produced
  3. causes: cutaneous vasodilation -> extremity warming -> cooling of core temp-> sleep initiation
  4. cont rising after onset of sleep for appx 4 hrs after sleep initiation (peak -= nadir), then steady decrease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is SCN and what is its roel?

A

suprachiasmic nucleus; “switch board” for sleep: transfers inputs to sleep regulating organs around the CNS and body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is NADIR?

A

peak in reduction in core temp (caused by melatonin) ; appx 4hrs after sleep onset, then steady decline, in melatonin, leading to incr core temp (decr periph temp) and cortisol release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Briefly describe the physiology and role of cortisol in sleep.

A

peak upon awakening (24 hour cycle)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

briefly describe physiology of early sleep (sleep onset to mid-sleep)

A
cutaneous vasodilation (melat) hence cooling of core: peaks at 4 hrs (nadir) 
predominantly slow wave (RESTORATIVE sleep)
decr. BP and sympathetic tone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

briefly describe physiology of onset of sleep

A

darkness triggers melatonin -> cutaneous vasodilation-> core temp cooling–> sleep initiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Briefly describe physiology of LATE sleep:

A

mid-sleep - waking

  • declining melt.
  • rising cortisol –> rising BP, sympath tone
  • increasing core temp, decreasing skin temp
  • longer REM periods (imp for FEAR extinguishing)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Sleep entraining and light

A

intensity, spectra, timing and duration of exposure all affect SCN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the unit of light intensity?

A

lux
bright sunlight = 100K lux
moonless night 8 orders less than bright sunny day, yet human eye still able to detect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the lengths of visible light spectra? What is the length of blue light?

A

kelvin ; visible spectrum = 400nm(violet) to 700nm (red)
blue light 420-480 nM
Kelvin= unit of light colour: Higher kelvin = cooler light
blue light = melatonin suppression

NB: home lighting can cause almost 100% melatonin suppression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is the effect of blue light on sleep?

A

melatonin suppression
incr cortisol , BP, HR, sypath tone, alertness, core body temp
- inhibits sleep onset and shifts the sleep cycle later

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What happens physiologically with westward travel and how can it be reset?

A
  • delayed phase shift (>24hrs) => delayed onset sleep
  • NB: can occur w/ home lighting, long days
  • “night owls” more susceptible to delayed phase shifts
  • melatonin can be helpful
    Reset forward!
  • effects: decreasedndaytime activity/ attention, positive affect, sociability, REM sleep, melatonin
  • metabolic effects: decreased caloric burn, leptin and core body temp amplitude max. => incr appetite and insulin resistance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What happens physiologically w/ eatbound travel and how can it be reset?

A

cycle shorter than 24 hrs => advanced onset sleep
gradual lengthening of clock required: e.g. delay light exposure in the morning
reset backwards

27
Q

what are the general principles of sleep entrainment?

A

gradual reset
backwards for advanced (eastbound travel)
forward for delayed (westbound travel)
SLEEP CYCLE <24 hrs (ADVANCED) increments of appx 10 min or less; e.g. delay light exposure, or wake up time mane by 10 min (or less)
SLEEP CYCLE > 24 hrs (DELAYED): set backwards by 20 min or less (limit light exposure earlier in the evening, etc.)

28
Q

T/F:
A) skipped, late or low-carb breakfast increase cortisol rise in the morning
B) Eating breakfast shortly after waking may help shift wake-up time earlier
C) eating a high carb breakfast may improve sleep-wakefulness transition
D) eating a carb-rich dinner can help reduce sleep latency

A

A) false: carbs and food in general early in the morning improve cortisol spike, hence can aid awaking
B) true
C) true
D) FALSE: carbs are “energising” and should be shifted to earlier meals if someone has difficulties falling asleep; if the problem is the opposite, ie falling asleep too early (e.g. elderly) a high carb dinner may help delay sleep onset

29
Q

T/F:
A) body temp during sleep has 3 main modifiers: 1. heat producing core (usually homeostatic) 2. heat-losing peripheral body (varies acc to environmental temp and blood flow) and 3. ambient temperature
B) the body core temp is at its peak at waking and will gradually decrease as the day goes, this helps the onset of sleep at night
C) blood osmolality is higher in the late afternoon to increase blood flow to vital organs
D) it is important to keep well hydrated during the afternoon in order to improve onset of sleep
E) sleep deprivation increases cortisol levels at night

A

A) TRUE
B) FALSE: normally the body core temp will raise during afternoon and extremities will go down in temp, during the night the opposite will occur
C) TRUE: higher blood osmolality in the late afternoon leads to higher afternoon peak in core temp; increasing blood flow to vital organs and less output to periph body
D) TRUE: decreased fluid intake during afternoon can lead to reduced amount of cutanueous blood flow needed for core cooling at night, increase cardiac activation, sympathetic tone (a state of stress)

30
Q

T/F:
A) as well as their central sedative effect, benzodiazepines help to cool down the core, hence aid in improving onset of sleep
B) ambient temperature is a strong determinant of periphearl body temp
C) sleep deprivation increases cortisol levels at night
D) decrease in peripheral body temperature is beneficial to advance onset of sleep

A

A) TRUE : benzodiazepines, yoga, meditation and autogenic training all produce similar effect in the body’s natural shunting of blood into extremities
B) TRUE
C) TRUE
FALSE: peripheral body needs to be warm to promote core temperature drop (core body temp = “thermostat”)

31
Q

Name populations more sensitive to melatonin suppression

A

behavioural disorders
bipolar and seasonal affective do!!!
elderly (partially due to opacity of cataracts)
affective do

32
Q

T/F:
A) melatonin suppression is not associated w/ affective d/o
B) melatonin suppression correlates w/ cataracts
C) a person w/ bipolar do has appx 45% decrease of melatonin secretion
D) behavioural disorders have known association w/ behaviorally induced insufficient sleep syndrome (BIISS)

A

A) False (it is, particularly strong assoc is w/ depression and bipolar do)
B) TRUE
C) TRUE
D) False: alcohol abuse, stress, depression, long work hours, age 30-39 have known assoc.

33
Q

what are the main characteristics of BIISS?

A
  1. inadequate sleep for functional performance
  2. voluntary restriction of sleep time
  3. longer sleep on weekends
  4. disparity betw need and obtained
34
Q

What is the prevalence of BIISS amongst general ppn?

and what are its main associations?

A
7-20%
younger age (30-39
alcohol abuse
longer work hours (>40/week)
stress
depression
35
Q

Define insomnia and what conditions is it known to be associated with?

A
  1. difficulty initiating and / or maintaining sleep
  2. day time consequences
  3. adequate sleep opportunity
  4. at least 3 months, at least 3x/week
  5. fatigue, malaiese, sleepiness
    concentration and memory impairment
    decreased motivation
    mood disturbance/ irritability
    errors or accidents
    physical symptoms: headaches, gi distress
    persistent worry about sleep
36
Q

define OSA

A
  1. recurrent apnoea or hypopnoea during sleep, at least 10 sec to 0ne min
    AHI Apnoea-Hypopnoea Index: polysomnography
37
Q

AHI classes: MILD

A

5-15

38
Q

AHI classes: MODERATE

A

15-30

39
Q

AHI classes: SEVERE

A

30+

40
Q

prevalence of OSA

A

26% gen pop; 80% undiagnosed

41
Q

what are the known associations of OSA

A
  1. overweight/ obese
  2. metabolic syndr
  3. HTN
  4. incr neck circumf
  5. loud snoring
42
Q

define restless leg sy (RSL)

A

feeling an urge to move legs
worse in the evening
movement helps relieve
not due to other cause

43
Q

prevalence of RLS and known associations

A

5-15% US ppn
periodic movements of sleep (85% of pat w/ RLS)
disruptions of sleep
fatigue
periodic involuntary and jerky movemnts of limbs while awake or at rest

44
Q

define short sleep misperception

A

mismatch betw perceived duration and actual duration of sleep (polysomnograpy)

45
Q

what are the most common conditions assoc w/ secondary insomnia?

A
medications, vascular dysfunction (peripheral hypoperfusion, vasospasm) 
visual impairment (melatinin, and circ rhythm) 
renin-angiotensin dysfunction (fluid balance)
46
Q

define narcolepsy

A

sudden incpntrollable onset of sleep: needs referral

47
Q

periodic limb movements

A

occur at about 30sec interval during sleep
incr freq w/ age (esp >50)
oft assoc w/ RLS
patients may not be aware

48
Q

T/F:
A) healthy sleep is associated with lower cortisol and glucose levels, greater insulin sensitivity, lower daytime leptin levels,
B) short duration and disrupted sleep correlates w/ elevated BMI, obesity (2xincr risk), metabolic syndr., T2D
C) impaired sleep (quality and / or duration) is assoc w/ lower sympathetic tone and BP, increased stamina and faster cardiovasc recovery time
D) short sleep correlates w/ refractory HTN, increased incidence of heart attacks and cardiovasc. dis deaths, vasospasmic disorders

A

A) FALSE: higher daytime leptin, reduced food seeking beh. , poor sleep on the other hand is assoc with higher glucose, cortisol, insulin resistance, lower day time leptin and increased intake of carbohydrate dense foods; higher calorie intake, part. from sat fats
B) TRUE
C) FALSE: impaired sleep = increased sympt tone and BP (partic nocturnal), reduced nght time periph perf., incr night time core temp.
D) true

49
Q

T/F:

A) Heathy duration and quality of sleep lead to more REM sleep- the most restorative phase of sleep
B) higher REM sleep = enhanced learning and memory, faster cognitive processing, greater anxiety and fear extinguishing
C) short or impaired sleep = less slow wave and REM => less neural tissue regeneration due to reduced Brain Derived Neurotropic factor (key substance in regeneration of neural tissues) , impaired learning and memory, emotional distress, impaired moral judgment, misinterpretation of social cues, decreased alertness and cognitive processing speed, diminished fear extinguishing in amygdala

A

A) FALSE: NHeathy duration and quality of sleep lead to more slow wave (STAGE 3 , deepest, most restorative stage of non-REM sleep) –>enhanced
B) TRUE
C) True

50
Q

Short sleep correlates with all but:

a) affective dos
b) premenstrual syndrome
c) worsening of PTSD if sleep deprived after the event
d) traumatic brain injury is worse is sleep deprived 2 weeks prior the injury

A

a) true
b) true
C) False: if sleep deprived 2 weeks prior to event
D) false: before and/ or follows the injury

51
Q
T/F: 
sleep disruption and shortened duration correlate w/ the following Ca: 
A) Breast
B) AML (acute myeloyd leuk)
C) Prostate
D) colorectal cancer
E) skin cancer
F)  Endometrial
G) Multiple Myeloma
A

answer: E and G are false

52
Q

Lifestyle sleep interventions.

A
  1. bed for sleep
  2. regular routine
  3. incr periph circulation: bath/ shower/ socks/ warm beverage
  4. minimise noise and other stimuli
  5. increase daytime light exposure (ideally natural light)
  6. increase daytime PA
  7. decrease light at night use 2500 Kelvin warm spectrum lights
  8. Diet: eliminate caffeinated beverages late afternoon/ evening; maintain hydration throughout afternoon, eliminate after dinner snacking, avoid high sodium foods (vasoconstriction)
  9. optimise BMI
    10 minimise stress, develop wind-down routine
  10. mitigate night time worrying, ruminating, etc. (MBSR, meditation)
  11. CBTI
53
Q

T/F:
A) CBTI is as good as medications for insomnia but has better side effect profile
B) behavioural methods (e.g. sleep restriction) have been examined in RCTs are backed by moderate to high quality evidence, meeting the EBT (evidence based psychological treatment) criteria for adults 18 and over
C) cognitive and behavioural strategies alone or in combination have been shown to facilitate getting off sleep medications and sustaining sleep over time
D) cognitive and behavioral therapies have been shown to reduce daytime fatigue

A

A) true: CBTI should be used as first line treatment for insomnia, over medications, CBTI has more sustained benefits compared to meds
B) False: behavioural methods (e.g. sleep restriction) have been examined in RCTs are backed by moderate to high quality evidence, meeting the EBT criteria for adults >60 and over
C) true
D) True, although limited evidence

54
Q

T/F:
Number of behaviour and cognitive strategies have been researched and shown to be effective for insomnia for older people, these include:

A) stimulus control shown to be effective in mod to high qual RCTs and partially meets the EBT criteria for adults >60yo
B) relaxation training therapy: shown to be effective in mod to high qual RCTs, did not meet EBT for adults >60
C) sleep hygiene: did not meet EBT for >60 yo
D) CBT : cognitive restructuring
E) hypnosis: mod level of evidence, several RCTs

A
A) true
B) True
C) true
D) true
E) false
55
Q

t/f: Melatonin
A) significant interindivid variation in endogenous melat production
B) efficacious for jatlag, circadian rhythm do’s and insomnia
C) very safe, no evidence of adverse effects at typical doses (1-6 mg) or interactions
D) supplementation does not seem to suppress endogenous melatonin
E) sublingual preps have better bioavailability

A
A) true
B) FALSE: mixed evid for insomnia
C) FALSE: but poss interaction w/ CytochrP450 drugs
D) TRUE
E) TRue
56
Q

T/F Sedatives and hypnotics:
A) prescription strength hypnotic medications assoc w/ significant increase in death rates, particularly in elderly
B) increased all cause mortality in all age gps from overdose, car accidents, falls, depression, cancer and suicide

A

A) FAlse: in death rates in adults 18-55

B) TRUE

57
Q

Interventions for Delayed onset of sleep

A
  1. optimise environment and body temp.
  2. light: incr morning exposure, increase afternoon PA (outdoors is possible), decrease light at night
  3. diet; reduce/ eliminate night time caff. , alcohol, sodim, carb-rich breakfst, low carb dinner
  4. stress: start winding down at least 1 hour before sleep
58
Q

Interventions for sleep fragmentation/ difficulty maintaining sleep:

A
  1. optimise environment and body temp.
  2. light: incr morning exposure, increase afternoon PA (outdoors is possible), decrease light at night (use red-toned ligths- high Kelvin)
  3. diet; ncrease late afternoon hydration, avoid evening/ late pm diuretics (e.g caffeine, alcohol, soda)
  4. stress: mitigate night time worries/ ruminations
59
Q

Interventions for early waking

A
  1. optimise environment
  2. light: avoid bright lightsuntil ideal wake up time, increase late afternoon and evening sunlight, increase afternoon/ evening PA
  3. use blue lights until one hour to bedtime
  4. diet: avoid eating or caffeine until 30-60 min after ideal wake up time, shift carbs from breakfast to dinner
60
Q

interventions for jetlag travelling EAST

A

optimise environment
Light: exposure to blue light, pref outoors, close to new ideal wake up time
dim light only: one hour before new ideal sleep time
diet: hearty breakfast within 30-45 min of nww ideal wake up time
melatonin 1mg sl one hour before new ideal sleep time

61
Q

Interventions for JEt lag traveling WEST

A

late afternoon/ early evening bright light exposure, pref outdoors; avoid dim lights until 1 hour before bedtime
diet: hearty breakfst within 30-45 min after ideal wake up time
complex carbohydrate-rich dinner two to three hours before new ideal sleep time
melatonin 1mg sl one hour bef new ideal bed time

62
Q

MINI SLEEP ASSESSMENT

A
  • typical weekday hours of sleep
  • typical weekend ours of sleep
  • perceived sleep quality
  • RED flags: <7 or > 9hr duration, 1or more weekday-weekend difference, irregular sleep timing, duration (esp shift work), poor quality of sleep
  • frequency of day time fatigue (fatigue inhibiting day time activities) , sleepiness or difficulties waking up
  • frequency and type of sleep disturbance:
    • onset >20 min
    • waking early (< 7-8 hrs)
    • prolonged wakefulness after inital sleep onset
    • fall asleep >8hrs before ideal wake up time
  • attitude tow sleep and sleep barriers (cavalier/ highly distressed?)
63
Q

brief OSA assessment:

A
STOP
Snoring
T tired (day time sleepiness, daily functioning) 
Observed apnoea episodes
Pressure (HTN or on meds) 
scoring: 
<2 low risk OSA
>2 high risk osa, refer
64
Q

Sleep Hygiene assessment

A
daytime naps of more than 30 min 
poor datime hydration
variations in sleep onset/ offset
prolonged non-sleep periods in bed
stimulating activities pre bed
going to bed stressed, angry, upset
reading, watching tv, eating inbed
uncomfortable bed/ bedroom
think, plan or worry in bed
caffeine, alcohol within 3 hours of bedtime